US blocks certification of new foreign-made solar inverters and BESS equipment

The US Federal Communications Commission (FCC) has tightened security requirements for electronic equipment used in energy infrastructure by adding foreign-made power inverters to its Covered List, preventing certification of new models for the US market that do not meet new national security requirements.

The decision, adopted by the FCC’s Public Safety and Homeland Security Bureau, affects both solar inverters and battery energy storage system (BESS) equipment and marks a significant change to the certification process for these products.

The restriction does not require the withdrawal of foreign-made inverters that have already been certified.

According to a clarification issued by the FCC, the measure applies only to new equipment authorizations. Models that already have an FCC ID may continue to be imported, sold and installed. However, new foreign-made models requiring regulatory approval will be unable to obtain certification while the restriction remains in force, unless they qualify under an exceptional conditional approval process.

The decision takes effect immediately and includes no transition period or broad exemptions.

The measure is intended to address cybersecurity risks to the U.S. electricity grid.

The approach differs from an assessment by the U.S. Department of Energy (DOE) earlier this year, which examined 30 Chinese-made inverters and found no conclusive evidence of hidden malicious hardware.

Instead, regulators argue that the risk lies in the remote communications capabilities of modern smart inverters. According to the FCC, wireless connectivity and remote firmware updates could allow foreign actors to alter equipment operation or disconnect solar installations remotely, potentially affecting critical infrastructure.

The regulation applies only to network-connected equipment. Fully isolated, air-gapped inverters or systems without remote communications capabilities are excluded.

According to figures cited in the regulatory documents, the United States expects to connect more than 58 GW of new solar and storage capacity over the next year.

However, domestic manufacturers currently supply only about 7% of the U.S. inverter market, leaving the country dependent on foreign suppliers for the remaining 93%.

While existing certified products remain available, the restriction is expected to affect future equipment availability as manufacturers introduce new product generations requiring fresh regulatory approvals.

The document also warns that changing inverter suppliers during project development could require new interconnection studies.

In the United States, grid interconnection agreements are linked to a specific inverter model and its electrical characteristics. Replacing that equipment may be considered a material modification, requiring developers to repeat interconnection studies and delaying project completion.

The regulation is based on the location of final assembly rather than company ownership.

A US-owned company manufacturing inverters outside the country would still be subject to the restriction, while foreign manufacturers assembling products in U.S. facilities may continue applying for approvals if they comply with federal domestic-content requirements.

The regulation also includes a conditional approval pathway for certain foreign manufacturers.

Under the process, administered jointly by the US Department of Homeland Security and the US Department of Defense, manufacturers may obtain approval if they demonstrate their products do not pose an unacceptable national security risk. To qualify, companies must submit their supply chains and firmware architecture to federal audits and provide a binding plan to move final assembly to US-based manufacturing facilities.

From pv magazine España